Hello!
I have a computer with a fast internet connection, my ping is 30 according to online tests, yet I keep having input lag. I bought the game yesterday, and I was a beta player, and I didn't use to have this kind of a lag before during beta and the trial weekends. FPS is usually between 10-20 and I'm on medium, but I could raise it by lower the graphics, however I doubt this is caused by lower FPS.
Now, whenever I press wasd, often the character keeps on moving even after letting go of the movement button, so it's hard to manouever in combat, as I often run through the enemies. Also whenever the "autorun" happens, that you keep on moving on for several seconds, during that time nothing works - no other buttons, the mouse, everything is frozen. Then it unfreezes and you can use the keyboard and mouse again, and then after few seconds it freezes again. It's about 10 or 20 seconds, no idea, not very long, inbetween the freezes.
Curiously enough, if you only press the movement button once, I don't have this freezing and it doesn't happen. Eg. you do w w w w w instead of wwwwwwww. Maybe it's CPU related as well?
I have an Acer laptop, 5750g with i5-2430 that has 2.4 Ghz with Turboboost up to 3.0, but for some strange reason the Turboboost doesn't seem to work now, and when I alttab to see cpu-z stats while playing ESO, it shows 790Mhz or 1500Mhz at most. When I tried uninstalling acer epowermanagement, then suddenly I didn't have this freezing lag, or rather, it happened very very rarely, but instead you had every few seconds classical FPS lag, where the screen would be jerky, so you'd look around and the screen would have short blips of freezing.
Now I didn't have this back in 2015, and my PC hasn't changed, so I'm not sure what's suddenly causing this. My internet connection is even faster than before, and everything is the same, I only updated Intel (I think it's the chipset). Not sure if reinstalling the chipset would help.